1. Field of the Invention
This invention relates to the structure of a semiconductor device having an unpackaged semiconductor chip mounted on a mounting board via a socket.
2. Background Art
Conventionally known methods of mounting a semiconductor device on a mounting board include methods of bonding a packaged, in most cases, semiconductor chip to the mounting board with solder, mounting a packaged semiconductor chip on the mounting board by inserting it into a socket as with CPUs for personal computers, and mounting a semiconductor chip via bumps. In any of these methods, the device is mounted parallel to the mounting board.
However, in these methods, the area of the mounting board depends on the area of the major surface of the semiconductor chip, and is restricted thereby. Moreover, in the case of mounting with solder, when there is trouble with a semiconductor chip, peeling it off from the mounting board and remounting take much time and effort. Thus there is a problem of increasing cost in conventional techniques.
A conventional technique is disclosed in JP 11-067985A. In this technique, a contact portion is formed on one side of a bare-chip semiconductor pellet. The semiconductor pellet is mounted into a socket having a connection terminal for a chip inside and an external connection terminal outside. A metal film of the semiconductor pellet is connected mechanically to the connection terminal of the socket. The semiconductor pellet can be easily inserted into and extracted from the socket. A plurality of semiconductor pellets can be mounted in parallel. However, in this technique, because the semiconductor chip is arranged perpendicular to the mounting board, heat generated from the semiconductor chip is less likely to escape through the mounting board than in conventional techniques where the semiconductor chip is laid down. Thus there is a problem of heat dissipation in such techniques.